Adrenal Disorders in Horses

Health problems related to either the adrenal cortex or adrenal medulla are rare in horses.

An overgrowth of adrenal cortex tissue can cause muscle wasting, bulging fat deposits above the eyes, a ravenous appetite, delayed shedding of the coat, and lack of energy. Primary adrenal gland disease is a very uncommon cause of hyperadrenocorticism in horses, but pituitary pars intermedia dysfunction (PPID or Cushing’s disease) can elevate adrenal production of cortisol.

Some foals and adult horses develop hypoadrenocorticism as a result of a critical illness. This may be due to a systemic inflammatory response, drug effects, or other factors related to the primary disease, and normal function of the adrenal cortex usually returns as the horse recovers.

Not all tumors of the adrenal medulla cause signs of disease, though some can secrete adrenaline and bring about colic, sweating, tremors, dilated pupils, and a rapid heartbeat in the horse.

Horse owners who notice unusual physical signs or behavior in their horses should consult a veterinarian to diagnose and treat disease.